Improved Chemical Control for the Mexican Rice Borer (Lepidoptera: Crambidae) in Sugarcane: Larval Exposure, a Novel Scouting Method, and Efficacy of a Single Aerial Insecticide Application

Abstract

A three-treatment aerial application insecticide experiment was conducted in five commercial sugarcane, Saccharum spp., fields in south Texas to evaluate the use of pheromone traps for improving chemical control of the Mexican rice borer, Eoreuma loftini (Dyar), in 2009 and 2010. A threshold of 20 moths/trap/wk was used to initiate monitoring for larval infestations. The percentage of stalks with larvae on plant surfaces was directly related to the number of moths trapped. Reductions in borer injury and adult emergence were detected when a threshold of >5% of stalks with larvae present on plant surfaces was used to trigger insecticide applications. Novaluron provided superior control compared with beta-cyfluthrin; novaluron treated plots were associated with a 14% increase in sugar production. A greenhouse experiment investigating establishment and behavior of E. loftini larvae on two phenological stages of stalkborer resistant, HoCP 85-845, and susceptible, HoCP 00-950, sugarcane cultivars determined that more than half of larvae on HoCP 00-950 and > 25% on HoCP 85-845 tunneled inside leaf mid-ribs within 1 d of eclosion, protected therein from biological and chemical control tactics. Exposure time of larvae averaged < 1 wk for all treatments and was shortest on immature HoCP 00-950 and longest on mature HoCP 85-845. This study shows a short window of vulnerability of E. loftini larvae to insecticide applications, and demonstrates the potential utility of pheromone traps for improving insecticide intervention timing such that a single properly timed application may be all that is required.

Resistencia varietal al ataque por Diatraea spp. (Lepidoptera: Crambidae) en caña de azúcar

“…Letras no comunes implican diferencia estadística en la prueba de separación de medias de Bonferroni al 5 %. (Hensley y Long 1969;Hensley 1971;White y Hensley 1987;Wilson et al 2012) y se estima que ayuda a controlar cerca del 40 % de la emergencia de adultos de la plaga (Bessin et al 1990a). En cada país, la caracterización de variedades de caña de azúcar resistentes a barrenadores depende en gran medida de la o las especies que generan las mayores pérdidas económicas y de las estrategias de selección que se practiquen al interior de los programas de mejoramiento; es así como en Estados Unidos sus programas de manejo integrado de plagas integran el uso de variedades resistentes las cuales han sido seleccionadas principalmente para E. loftini y D. saccharalis (White et al 2010) donde no solo evalúan variedades resistentes, sino que han llegado a generar y evaluar líneas de retrocruzamiento con Saccharum spontaneum L. y Erianthus sp.…”

Sugarcane Stem Borers of the Colombian Cauca River Valley: Current Pest Status, Biology, and Control

“…However, even though direct selection for borer resistance was not carried out, a recurrent selection program was initiated in Louisiana in 1986 to develop resistant germplasm to incorporate in the crosses of the commercial breeding programs (White et al 2011). Suppression of D. saccharalis in Louisiana was achieved largely through a combination of insecticides and resistant cultivars before the arrival of E. loftini, a species that now represents more than 95% of the total stem borer population (Wilson et al 2012). Different resistance mechanisms have been recognized against D. saccharalis; leaf sheath appression coupled with rind hardness in younger internodes are forms of mechanical antibiosis that delay larval entry, increase the mortality of young larvae, and reduce injury to stalks (Martin et al 1975;White 1993).…”

“…Because current commercial cultivars exhibit a wide range of variation in susceptibility to borer attack in Colombia (Ranjel et al 2003), the development and release of varieties with good levels of resistance to borers could make an important contribution to IPM programs in the country (White et al 2001;Reay-Jones et al 2003Wilson et al 2012). used oviposition choice tests to assess varietal resistance under greenhouse conditions and did not find any indication of antixenosis in the varieties tested, but the development and survival of larvae was affected by cultivar, suggesting antibiotic factors were present.…”

Hemipteran Pests of Sugarcane in North America

“…Production of sugarcane in Mexico is concentrated on the coastal plains of both the Gulf and Pacific coasts with the states of Veracruz, San Luis Potosi, and Jalisco, accounting for the majority of sugar produced in the country [2]. The primary focus of entomological research in North America has focused on lepidopteran stem borers as this pest guild is considered the most economically important [3,4,5]. However, a complex of piercing-sucking insects (Hemiptera) that also attack sugarcane in this region has received relatively little attention from researchers.…”